chore: move to public gitea instance and drop project-local gitea MCP

- Remove the project-local gitea MCP (opencode.json) and gitea-mcp-server
  from the dev shell — the gitea MCP is now installed globally and points
  at https://gitea.edley.me
- Update README/project.md links and the flake package homepage to the
  new public instance
- The GITEA_ACCESS_TOKEN for the old homeserver is removed from
  .secrets.env (gitignored); the global token from /run/secrets is used

project.md

@@ -42,7 +42,7 @@ and streams it. No NDI compatibility of any form.
 | Discovery          | UDP multicast peer discovery (identical to `obs-teleport`)     |
 | Target quality     | Initial release: 1920x1080 @ 30 fps, balanced JPEG quality     |
 | Protocol target    | Latest `obs-teleport` release (protocol contract below)        |
-| Remote git         | Self-hosted Gitea at `http://homeserver:3050/`                 |
+| Remote git         | Public self-hosted Gitea at `https://gitea.edley.me/`         |
 
 ## Teleport Protocol Contract